Letencrypt only adds aliasdomains with redirect as "redirect"

short description

Letsencrypt only adds alias domains to the SAN if they are set to redirect mode "redirect". If the redirect mode is "last" they are not added.

correct behaviour

All alias domains should be added to the SAN

environment

Server OS: Debian
Server OS version: jessie
ISPConfig version: 3.17p1
nginx version: nginx/1.6.2

PHP 5.6.30-0+deb8u1 (cli) (built: Feb  8 2017 08:50:21)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
    with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies

more detail

If the nginx rewrite is like this:

        if ($http_host = "domain.com.au") {
            rewrite ^(?!/\b(sites/domain.com.au|stats|error)\b)/(.*)$ /sites/domain.com.au/$2 last;
        }

Then it does not get added to the SAN. This is reflected in the ispconfig logs.